I own Red Dead (the standard disc) and in order to get the DLC, I bought undead nightmare. To my surprise, I cant download its content to my XBox so I can have access to all content with the standard game disc.
Here are the questions: To have all online content I must use the Undead disc but does this give me access to all of the online modes in the game? Do I need to swap discs between the 2 games in order to be able to play all online gametypes?
I am also going for achievements. Can I get all the online achievements using just the undead nightmare disc? Does it create a second list of achievements so that I have to get each one twice? (I am referring to what happened with the Arkham Asylum GOTY edition making two different lists of the same achievements on accounts)